Why are there now not only delays but also hesitations ? The Brexit result after the Vote was in fact a surprise !
What was not anticipated were the complex reasons for such a vote and also the numerous detailed negotiations needed to sever relations and obligations with the EU ! These could well take much longer than the 2 years prescribed by EU Treaties at present.
Britain now has a new Prime Minister, Mrs Theresa May, who supported the Brexit initiative before the Vote. She will be responsible for the Negotiations, but the atmosphere now seems to be less euphorique for leaving the EU than just after the Vote.
There is one pre-condition in EU Treaties : Britain must notify Brussels that it wants to start negotiations to leave the EU. However to do this the Prime Minister must get the Authority after a vote by MPs in the House of Commons ! That could be a real obstacle !
Why ? Because circumstances in Britain and the EU are changing ! One key issue is a good example ! The uncontrolled arrival of immigrants in the EU from the war torn Middle East (and other "hot spots" of the World) is due to badly controlled EU frontiers ! Even Germany now wants reinforced controls not only at External EU frontiers but also at internal EU boundaries.
This means the Schengen Treaty but others also must be reviewed and changed ! Was "immigration" not the key issue which resulted in the Brexit Vote !
When Parliaments reassemble after the Summer recess, "Brexit or not" will be a key issue everywhere in the EU !